Preamps

Another nod for Ayre. I also recommend T+A P3000HV. 

There is a demo T+A on Agon, 

https://www.audiogon.com/listings/lis8hd59-t-a-elektroakustik-p3000hv-available-in-titanium-and-silv...

And this is hot off the press for you to consider, 

https://www.stereophile.com/content/emm-labs-dv2-da-processor

Should you choose to look into a Tube pre, ARC Ref6 should be on your list. I believe it will be a killer pre for your 625 S2 amp. 

@georgehifi said: ...going direct can sound absolutely stunning with unmatched transparency and dynamics with the good to best recordings, but then almost unlistenable with the bad recordings,
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Precisely my experience with a wonderful passive I auditioned that was much cleaner than the DAC volume control.  There were just too many recording where I really didn't want the band in the room because the mastering sucked.  A real conundrum.  Can I handle the truth? I'm back to that loosy-goosy search for a "sweet sounding" linestage.

It's my understanding that ARC preamps have issues when using a subwoofer and I have a JL Audio F112 v2 sub.

I think step #1 is to identify what you think the weaknesses of the Rowland are, and /or what you want further improved.
Honestly with out that its a crap shoot/
G

There were just too many recording where I really didn’t want the band in the room because the mastering sucked.

It shouldn’t be too hard to set the system up so when good recordings are played it goes source direct to poweramp, and you use the sources volume control.
But when bad recordings are played the source goes through an active preamp using it volume control that de-focuses them and makes them more listenable.

What’s needed is a source/preamp switcher to the poweramp/s.

Source direct outputs have to be disconnected from the amp inputs, and re-directed to the preamp inputs, and the preamp outputs then connected to the amps inputs. All done powered up with just one flick of a switch without any clicks, pops or bangs.

Cheers George